Jewel and pivot protector.



A. J. HOPEWELL. JEWEL AND PIVOTPROEGIOR. APPLICATION FILED SEPT. Iei me.

il 923@ 75 Patented Aug. 7, 1917.

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TTRNEYS ANDREW J'. HOPEWELL, OF EDINBURG, VIRGINIA.

JEWEL AND PIvoT PROTECTOR.

Specification of Letters Patent.

Patented Aug. '7, 1917.

Applicatioiuled September 18, 1916. Serial No. 120,681.

To all whom t may concern: o .Be it known that I, ANDREW J. HoPEwELi., a citizen of the United States, and a resident of. Edinburg, in the county Vof Shenandoah and State of Virginia, have invented a new and Improved Jewel and P ivot Protector, of which the following is a full, clear, and exact description.

The invention relates to watches and its object is to provide a new and improved jewel and pivot protector arranged to readily absorb slight jarswithout affecting the central position of the jewels and pivots of a balance wheel, to readily yield in case the watch is subjected to a of suiiicient force to endanger the safety of the jewels and pivots, and in case of a severe jar to yield and arrest the momentum of the balance wheel from every direction and to return the jewels and with them the balance staii to their normal central position.

Inorder to accomplish the desired result, use is made of a springdisk under tension in a lateral and axial direction, the disk having a central receptacle for the'jewels:

A practical embodiment of the'invention is represented in the accompanying drawings forming a part vof this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is an enlarged sectional side elevation of the jewel and pivot protector as l applied to the stai of the balance wheel or' a watch;

Fig. 2 is a similar view-of the same with the cap omitted and with the spring disk shown in position prior to its being sprung into nal position;

Fig. 3 is a plan view of the jewel and pivot protector; and

Fig. 4 is an enlarged perspective view of the spring disk.

The upper plate or bridge 10 of a watch movement is shown attached to the lower plate or potance 11, and both plates are provided with recesses 12 and 13 in which tspring disks 14 and 15 each provided with a receptacle 16 for the reception of kthe cap and hole jewels 17 and 18, of which the hole jewel 18 is engaged by the corresponding pivot 19 of the staff 20 of the balance wheel.

Each of the disks 14 and 15 is, provided with a spiral slot 21 to render the disk resilient in a lateral as well as in an axial direction. Each disk 14 and 15 is provided with a central concave bearing 22 at the entrance to the jewel receptacle 16 and this bearing 22 is seated on a convex seat formed on the bottom of the corresponding recess `12 or 13. The seat 23 is provided with an aperture 25 through which extends loosely the enlarged portion 26 of the corresponding pivot 19, it being understood that this enlarged portion 26 does not touch the wall of the aperture 25 under ordinary circumstances but is liable to touch the said walls in case the watch is subjected to a very severe jar as hereinafter more fully explained. The shoulders 27 on the staff 20 adjacent the enlarged pivot portions 26 engage the concave faces of the seats 23 to relieve the jewel of undue strain in case of an axial jar on the balance statt 20.

In order to hold each spring disk 14 or 15 in position in its corresponding recess 12, 13, and under tension in an axial direction, use is made of caps 30 fitting into the corresponding recesses 12 and 13 and bearing with their margins on the margins of the spring disks 14 and 15 to force the said margins into contact with the bottoms 24 of the recesses 12 and 13. It is understood that each spring disk 14 or 15 is normally fiat, as shown in Fig. 2, and when seated on the seat .23 its edge extends a distance from the bottom 24 of the corresponding recess 12 or 13, but when the corresponding cap 30 is placed in position and exerts pressure against the margin of the corresponding spring disk 14 or 15 then the latter is engaged at its edge with the bottom 24 of the corresponding recess 12 or 13 thus flexing and placing the spring disks 14 and 15 under tension in an axial direction.

In order to removably attach each cap 30 tothe corresponding plate 10 or 11, use is made of projections 31 formed on the peripheral edge of each cap and adapted to pass through openings 32 into a groove 33 formed in the wall of the corresponding recesses 12 or 13. Thus when a cap is placed in position and is pressed inward then the corresponding spring disk 14 or 15 is placed under tension and when this position is reached the cap is given a short turn so as to engage the projections 31 with the groove 33 to lock the cap in place on the wall of the corresponding recess 12 or 13. Each of the caps 30 is provided with recesses 35 for the reception of a Spanner wrench to permit of conveniently turning the cap when plac- .leas't shock or impulse.

ing vthe same in osition or when removing the same from t e corresponding plate 10 or 11. Each cap is also provided with a central aperture 36 into which projects the outer end of the corresponding jewel receptacle 16.

The spring disks 14 and 15 with 'the jewels held thereon'can be readily placed in position in the recesses 12 and 13 of the plates 10 and 11 to engage the pivots 19 with the. -hole jewels 18 and then the spring disks 14 and 15 can be readily fastened in place by the use of the caps which also place the spring disks under tension in an axial di- (l noticed that the spring setting shown and described holds the jewels in perfectly true u .center positions, and by the bearings 22 engaging the seats '23 under pressure the spring disks are not liable to be shifted under ordinary shocks, butin case of a shock or a jar that may .endanger the safety of the jewels and pivots thespring disks yield in a lateral direction and thus prevent injury to the jewels and pivots. The spring disks 14 and 15 immediately return to their normal 'positions after the shock `or jar has passed so as to maintain the balance staff in' true position. j

- In case of a very severe shock in a lateral direction, the spring disks 14 and 15 yield and allow the enlarged portions 26 of the pivots 19 to strike against the walls of the openings 25 and thus-,arrest the momentum of the balance w'liifit vbeing understood that the enlarged portions 26 are suiliciently strong to prevent injury to the pivots v19. ,It is understood that after the shock or jar ceases the spring disks immediately return the balance staff to its normalposition.

.The spring setting shown and described is very simple and durable in construction and may be made in several standard sizes to suit the size of the watch on which it is to be applied. It will also be noticed that the spring setting can be quickly applied without requiring special 'tools or the like.A

Having thus described myl invention, I claim as new and desire to secure by Letters Patent:

1. A spring setting for the protection of jewels' and pivots, comprising a' disk having a spiral slot for rendering the disk resilient, the disk having a central receptacle for the jewels, the said disk having on one side a j central concave bearing adapted to be seated of the balance stad and with which the I shoulder of stati is adapted to engage, a disk held in the said recess and having a spiral slot to render the disk resilient, the said disk having a central receptacle for 'the jewels and having a centraljconcave bearing engaging the said seat, and a-cap held on the said plate and closing the said recess, the margin of the cap bearing on the margin 'of the disk to flex the same and thereby yput it yunder tension in an axial direction.

3. In a spring setting for the protection of jewels and pivots of a balance wheel, a plate having'a recess provided at its bottom with a central convex seat having a central aperture for the passage of the pivot of the balance stali', a disk held in the said recess and having a spiral slot to render 'the disk resilient, the said disk having a central receptacle for the jewels and having a central concave bearing engaging the said seat, a cap held on the said plate and closing the said recess,

the margin of the cap bearing on the margin d of the disk to press *the edge of the disk into engagement with the bottom of the recess, the said plate having a groove inthe wall of the said recess and openings leading from the face of the plate to the said groove, and the said cap` having projections at its edge adapted to engage the said openings and the said groove to lock the cap in position on the plate.

4. In a spring setting for the protection of the jewels and pivots of a balance wheel, plates having recesses provided at their bottoms with central convex seats each having a central aperture for the corresponding pivot of the staili of the balance wheel to pass through, disks held in the said plate recesses and having receptacles for the jewels, the disks having spiral slots to render the disks resilient, and the disks having central con# cave bearings seated on the said seats, and caps removably attached to the saidplates and closing the said recesses, the margins of the said caps bearing on the margins of 'the said disks to flex the disks and press the edges thereof into contact with the bottoms of the said recesses.

ANDREW J'. HOPEWELL. j

Witnesses:

B. S. Rau, J'. B. CLEM, Jr. 

